Apparatus for controlling the movements of a flat knitting machine

ABSTRACT

The abutment pins which control, e.g. reverse, the movements of a flat knitting machine are controlled such that the selected ones thereof are resiliently held in an operative position, e.g. by a spring, and hence need not be held in an operative position by the armature of an electromagnet under electrical tension. A control member moves all abutment pins to a withdrawn position where they are held by a permanent magnet, the field of which is then locally and selectively offset to release selected abutment pins, permitting them to be resiliently moved to the operative position. The control member then moves to retain the other abutment pins in the withdrawn position.

[ June 25, 1974 3,053,065 9/1962 Steiger...... 66/154 A MOVEMENTS OF A FLAT KNITTING MACHINE Primary Examiner-Ronald Feldbaum [75] Inventors: w'lhelm Hadam; Jul'gen Ploppa; Attorney, Agent, or Firm-Larson, Taylor and Hinds Ernst Goller, all of Reutlmgen, Germany [73 Assi nee: II. Stoll and Com an Reutlin en,

1 g Germany p g 57 ABSTRACT 1973 The abutment pins which control, e.g. reverse, the APPL 320 17 movements of a flat knitting machine are controlled such that the selected ones thereof are resiliently held in anoperative position, e.g. by a spring, and hence Foreign Application y Data need not be held in an operative position by the arma- Dec. 30, 1971 Germany............................ 2165538 ture of an electromagnet under electrical tension. A

control member moves all abutment pins to a with- U.S. 66/127, 66/154 A, 66/78 drawn position where they are held by a permanent Int. D04b 15/52 magnet, the field of which is then locally and selec- [58] Field of Search 66/125, 127, 78, 126, I54, tively offset to release selected abutment pins, permit- 66/ 5, 128 ting them to be resiliently moved to the operative position. The control member then moves to retain the [56] References Cited other abutment pins in the withdrawn position.

UNITED STATES PATENTS 3,035,426 5/1962 MacQueen.............................. 66/75 10 Claims, 8 Drawing Figures United States Patent Hadam et al.

[ APPARATUS FOR CONTROLLING THE [22] Filed:

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PATENTEDJHNBSW 3.818.727

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APPARATUS FOR CONTROLLING THE MOVEMENTS OF A FLAT KNITTING MACHINE BACKGROUND OF THE INVENTION- The invention relates to an apparatus for controlling the movements of a flat knitting machine.

By control of the movements of a flat knitting machine is meant, for example, control of the reversal of the thread guides, the cam parts and the adjustable abutments or stops with which such a machine is provided.

In one known form of control apparatus the movements of a flat knitting machine are controlled by electromagnets which, for example, are arranged at the ends of the machine frame in planes at right angles to the movement of the carriage and, when they are activated and hence under electrical tension, constitute traverse abutments for rods which are slidable on the carriage and serve as reversing elements for the machine.

Such an arrangement has the disadvantage that the abutments which are in the form of magnetic armatures are under electrical tension where and when they constitute traverse abutments. If now the carriage remains stationary in the zone at which it reverses as a result of a response to a safety device, for example, an over-load safety device, the abutments in the form of magnetic armatures remain under tension until the carriage has been moved out of this reversing zone. In certain circumstances the abutments under tension can heat up so much that the windings of the electro-magnets burn through. To prevent this, the electro-magnets, depending on the prevailing conditions, may be overdimensioned although this solution to the problem is both impracticable and uneconomical.

SUMMARYv OF THE INVENTION It is therefore a purpose of the present invention to provide a new and improved control arrangement which eliminates the above described difficulties.

In accordance with the present invention the problem is solved by the provision of a control apparatus wherein all of a set of abutment pins are offered, by actuation of a common slide means, to a controllable holding magnetic system furnished with a corresponding set of individually controllable poles and the holding effort of which system is produced by a permanent magnet, the said holding effort at a specified momenteither during the course, or at the end, of a carriage strokebeing withheld by a short impulse selectively transmitted or applied to appropriate ones of the control poles, the arrangement and operation of the apparatus being such that those abutment pins selected for controlling movement during the succeeding carriage stroke are released and restored under the influence of springs to upper operative positions, whereas the remaining abutment pins which continue to be held by the holding magnetic system during said specified moment are then subsequently positively held down and guarded against unintentional release by formations on the same common slide means.

Advantageously, the common slide means is longitudinally displaceable, to force down all the abutment pins into contact with the magnetic holding system by an over stroke, e.g. effected by a lever.

Thus, it is an object of this invention to provide a new and improved control mechanism for a flat knitting machine.

It is another object of this invention to provide a new and improved control mechanism for a flat knitting machine having abutment pins for controlling reversal of the machine, wherein a non-electric force holds the abutment pins in the operative position.

It is another object of this invention to provide, for controlling a flat knitting machine, a system of abutment pins which are held in the operative position by a spring means, and which includes a control means for withdrawing all of the abutment pins to be held in the withdrawn position by a permanent magnet, and then locally and selectively offsetting the effect of the permanent magnet on the selected abutment pins, permitting the latter to be spring-biased to the operative position, the control means retaining the remaining abutment pins in the withdrawn position.

Other'objects and advantages of the present invention will become apparent from the detailed description to follow, taken together with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a general perspective view of the control apparatus as seen from above.

FIG. 2 is a vertical sectional view taken on the line IIII of FIG. 1.

FIG. 2A is a horizontal sectional view taken on line 2A--2A of FIGS. 1 and 2.

FIG. 2B is a vertical sectional view taken along line 2B-2B of FIGS. 1 and 2.

FIG. 3 is a sectional view similar to FIG. 2, but with the abutment pins attracted.

FIG. 4 is a further sectional view similar to FIG. 2, but showing only selected ones of the abutment pins attracted.

FIG. 5 is a perspective illustration of the retaining magnetic system.

FIG. 6 is a crosssection taken on the line VIVI of FIG. 5.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT:

Referring to the drawings wherein like elements are represented by like numerals throughout the several views, it will be seen that axially displaceable abutment pins 6 are mounted in and guided by upper and lower guide plates 1 and 2 respectively. Pins 7 set transversely into the abutment pins 6 are guided in transverse grooves 14 cut in the lower plate 2. The grooves 14 are in communication with longitudinal groove 15 also formed in the plate 2. Mounted slidably within the longitudinal groove 15 is a slide 5 which has formed therein saw-toothed recesses 16. The recesses 16 are equally spaced apart at distances corresponding to those between the abutment pins 6. The slide 5 is moved by lever 10 mounted in the bearer plate 3 after, or during the course of each stroke of the machine carriage. The lever 10 is connected via suitable rivets 26 to an inverted U-shaped bracket 27 opened at the bottom, which bracket slides vertically in recessed grooves 28 on both sides of the slide 5. This vertical sliding movement of bracket 27 on slide 5 permits the rectilinear movement of the slide 5 as the lever 10 turns about its axis. The guide pins 7 projecting into the longitudinal groove 15 and into the recesses 16 in the slide 5 are positively pressed downwards, by virtue of the slanting wall 23 of said recesses in the transverse grooves 14 during the displacement of the slide into the position 5' indicated in FIG. 3. That is to say, all the abutment pins 6 are offered to the retaining or the holding magnetic system 18 and remain held against the surface 19 of this system by a magnetic force acting on permeable discs 11 of buffer elements 8, e.g. of metal and rubber, of the pins 6.

The abutment pins 6 which are required for reversing the working parts of a flat knitting machine by engagement of such pins by corresponding abutment slides 22, must be released from the holding magnetic system 18 to enable them to return to their upper operative positions under the restoring influence of compression springs 12. For this purpose the magnetic force exerted on selected abutment pins 6 must be removed for a short period. Such removal is effected by the fact that the magnetic field of a permanent magnet 24 incorporated in the holding magnetic system 18 is sufficiently weakened, by a temporary flow of current through coils 25 wound around pole pins 20, to permit corresponding abutment pins to be pulled away by the force of their respective springs 12. The magnetic field of a coil 25 compensates or weakens the field of the permanent magnet 24.

Considered in more detail, with reference to FIG. 6, the reference numeral 18 designates a housing for the common pole 19 and a magnetic intermediate plate 21, and the counter pole pins 20 are disposed in the holding magnetic system. The upper portion of each pole pin 20 defines, together with the surrounding portion of the common pole 19, an air gap which is filled by a diamagnetic bush 9, so that a magnetic effect is set up at this location. Each bush 9 assists in sealing the housing of the magnetic system and also provides a bearing for the relevant counter pole pin 20.

After the selection process, the slide 5 returns from the position 5' (FIG. 3) to the starting position (FIG. 4). As a consequence, the guide pins 7 of those abutment pins 6 which are released from the holding magnetic system 18, are pressed up by their respective springs 12 into the corresponding recesses 16. The remaining guide pins 7 are held down and guarded by the noses 17 of the slide 5 against unintentional detachment from the holding magnetic system 18 as seen in FIG. 4. Thus, in this particular figure only one of the abutment pins 6 in the row shown in FIGS. 2-4 is released from the holding magnetic system whereas the remaining three abutment pins thereof are held down.

The complete control apparatus is not confined to use at one position only and may, for example, be displaceable along a guide rail 13 during a variation in carriage stroke, and by the same amount. The apparatus may, for example, be used for the control of the carriage cams through the medium of cam slides. It is, however, to be clearly understood that the apparatus those skilled in the art without departing from the spirit and scope of the invention, as defined in the claims.

We claim: 1. An apparatus for controlling movement of a mov- 5 able member of a flat knitting machine comprising:

can also be used for any other appropriate control 6 such, for instance, as reversal of thread guides. Use of electrical switching elements instead of slides is also possible.

Although the invention has been described in considerable detail with respect to a preferred embodiment thereof, it will be apparent that the invention is capable of numerous modifications and variations apparent to a set of abutment pins, each pin of the set being movable between an inoperative position and an operative position, in the latter of which the pin is positioned to be engaged by the said movable member to thereby control the movement thereof, permanent magnet means for holding all of said pins in said inoperative position and spring means for urging each pin away from the holding force of the permanent magnet means to the operative Position, the force of said spring means being sufficiently great to keep away from the permanent magnet means a pin already spaced therefrom but insufficiently great to pull away from the permanent magnet means a pin, the end of which is being held by the permanent magnet means,

a control means for momentarily urging all of said abutment pins into holding engagement with the permanent magnet means,

and release means associated with each pin for offsetting the force of the permanent magnet means on that pin, permitting that pin to become disengaged from the permanent magnet means such that its spring means can move it to the operative position,

whereby, when the pins are held by the permanent magnet means, the release means of the selected pin is operated to release those pins so that they can move to the operative position.

2. An apparatus according to claim 1, said release means comprising a permanent magnet, a control pole associated with each abutment pin and extending from the permanent magnet towards its respective abutment pin, each control pole including a means for electrically magnetizing the same with a polarity opposing that of the permanent magnet so as to permit the abutment pin associated therewith to be released from holding contact with the permanent magnet to move under the influence of its spring means towards the operative position.

3. An apparatus according to claim 2, said control means including means for urging all of the pins of a group thereof into contact with the permanent magnet means in opposition to the spring means, for momentarily releasing the selected pins to move by the action of their respective spring means towards the operative position, and then for holding the remaining nonselected pins to prevent accidental movement thereof toward the operative position.

4. An apparatus according to claim 3, said abutment pins being arranged vertically and including transverse guide pins extending laterally therefrom, means for guiding the transverse pins vertically, the control means including a slide member movable horizontally and having one recess in the bottom thereof for each transverse pin of a group of aligned abutment pins, a portion of each recess being inclined and positioned to urge its respective transverse pin and hence also its associated abutment pin downwardly as the slide member moves in one direction, said slide member including a flat bottom edge adjacent each recess for holding the transverse pin of the adjacent recesses downwardly, said selected pins being movable upwardly back into the recesses when the slide member moves in the opposite direction, and said slide member including a nose portion which, upon further movement in said opposite direction, holds the remaining transverse pins downwardly to prevent accidental release from the pennanent magnet means of the non-selected abutment pins.

5. An apparatus according to claim 2, wherein the permanent magnet means has a common pole spaced from the permanent magnet, and said control poles being constituted by shoes of the permanent magnet, each of which control poles forms an air gap with the common pole, and wherein each of the control poles has a control winding, the magnetic induction in the said control pole being so weakened by the application of voltage to the control winding as to produce a reduced holding force within said air gap.

6. An apparatus according to claim 2, said permanent magnet being enclosed in a housing, said air gap being filled by a bush of diamagnetic material which assists in sealing the housing of the permanent magnet means and providing a bearing for its respective control pole.

7. An apparatus according to claim 1, wherein each of the abutment pins carries at its end adjacent the permanent magnet means a buffer element which serves as an armature and is so shaped as to be movable in three planes to thereby dampen the impact applied to the exterior thereof.

8. An apparatus according to claim 7, including a magnetic intermediate plate adjacent the permanent magnet and surrounding the control poles.

9. An apparatus according. to claim 1, wherein the control means has recesses associated with transverse pins attached to the abutment pins, the control means further including noses which, by action of such transverse pins, holds down and guards the respective abutment pins against unintentional release.

10.. An apparatus according to claim 1, wherein the control means is a slide member longitudinally displaceable under the action of a lever controlled by the knitting machine to force all of the abutment pins into contact with the permanent magnet means. 

1. An apparatus for controlling movement of a movable member of a flat knitting machine comprising: a set of abutment pins, each pin of the set being movable between an inoperative position and an operative position, in the latter of which the pin is positioned to be engaged by the said movable member to thereby control the movement thereof, a permanent magnet means for holding all of said pins in said inoperative position and spring means for urging each pin away from the holding force of the permanent magnet means to the operative position, the force of said spring means being sufficiently great to keep away from the permanent magnet means a pin already spaced therefrom but insufficiently great to pull away from the permanent magnet means a pin, the end of which is being held by the permanent magnet means, a control means for momentarily urging all of said abutment pins into holding engagement with the permanent magnet means, and release means associated with each pin for offsetting the force of the permanenT magnet means on that pin, permitting that pin to become disengaged from the permanent magnet means such that its spring means can move it to the operative position, whereby, when the pins are held by the permanent magnet means, the release means of the selected pin is operated to release those pins so that they can move to the operative position.
 2. An apparatus according to claim 1, said release means comprising a permanent magnet, a control pole associated with each abutment pin and extending from the permanent magnet towards its respective abutment pin, each control pole including a means for electrically magnetizing the same with a polarity opposing that of the permanent magnet so as to permit the abutment pin associated therewith to be released from holding contact with the permanent magnet to move under the influence of its spring means towards the operative position.
 3. An apparatus according to claim 2, said control means including means for urging all of the pins of a group thereof into contact with the permanent magnet means in opposition to the spring means, for momentarily releasing the selected pins to move by the action of their respective spring means towards the operative position, and then for holding the remaining non-selected pins to prevent accidental movement thereof toward the operative position.
 4. An apparatus according to claim 3, said abutment pins being arranged vertically and including transverse guide pins extending laterally therefrom, means for guiding the transverse pins vertically, the control means including a slide member movable horizontally and having one recess in the bottom thereof for each transverse pin of a group of aligned abutment pins, a portion of each recess being inclined and positioned to urge its respective transverse pin and hence also its associated abutment pin downwardly as the slide member moves in one direction, said slide member including a flat bottom edge adjacent each recess for holding the transverse pin of the adjacent recesses downwardly, said selected pins being movable upwardly back into the recesses when the slide member moves in the opposite direction, and said slide member including a nose portion which, upon further movement in said opposite direction, holds the remaining transverse pins downwardly to prevent accidental release from the permanent magnet means of the non-selected abutment pins.
 5. An apparatus according to claim 2, wherein the permanent magnet means has a common pole spaced from the permanent magnet, and said control poles being constituted by shoes of the permanent magnet, each of which control poles forms an air gap with the common pole, and wherein each of the control poles has a control winding, the magnetic induction in the said control pole being so weakened by the application of voltage to the control winding as to produce a reduced holding force within said air gap.
 6. An apparatus according to claim 2, said permanent magnet being enclosed in a housing, said air gap being filled by a bush of diamagnetic material which assists in sealing the housing of the permanent magnet means and providing a bearing for its respective control pole.
 7. An apparatus according to claim 1, wherein each of the abutment pins carries at its end adjacent the permanent magnet means a buffer element which serves as an armature and is so shaped as to be movable in three planes to thereby dampen the impact applied to the exterior thereof.
 8. An apparatus according to claim 7, including a magnetic intermediate plate adjacent the permanent magnet and surrounding the control poles.
 9. An apparatus according to claim 1, wherein the control means has recesses associated with transverse pins attached to the abutment pins, the control means further including noses which, by action of such transverse pins, holds down and guards the respective abutment pins against unintentional release. 10.. An apparatus according to claim 1, wherein the control means is a slide member longitudinally dIsplaceable under the action of a lever controlled by the knitting machine to force all of the abutment pins into contact with the permanent magnet means. 